1. Field of the Invention
The invention relates to a method of controlling access to a location, where access to the location is restricted by a lock mechanism. Further the invention relates to an access control system which allows suppliers of goods or services to access a location, which would otherwise prevent delivery of the goods or the services. Further the invention relates to an electronic key device, a lock control unit and a computer system for use in such a system, a storage module for use in such an electronic key device, and a method of managing a predetermined access right to a location.
2. Description of the Related Art
Particularly in blocks of flats or companies it is common that a number of outer or front doors or intermediate doors must be passed before getting to a point of service, such as an apartment door, a mailbox, a service station or a meter for appliances, an area to be cleaned, etc. For example in case of delivery of newspapers, the delivery man often has to gain access to a stairway in order to be able to deliver the newspapers at the locked private doors or put them into the letter boxes. It frequently causes great difficulties to the delivery men to find the correct keys in a large bundle of keys, and the locks are frequently exchanged without the delivery company being informed of this. For reasons of security it is also more and more common to lock doors or gates to backyards, residential areas or company properties, where for example refuse containers may be placed, so that the refuse collection firms have a problem quite similar to the firms which deliver newspapers. It will be appreciated that similar problems are faced by:                postmen        cleaning companies        emergency physicians        home help and other care workers        policemen        firemen        artisans        caretakers/superintendents        and others.        
Some of the above service providers require access on a daily basis, such as postmen, some may require access at certain time periods, such as on certain weekdays or at certain times of the day, for example a newspaper delivery man may require access between 6 a.m. and 9 a.m. Furthermore, different services/deliveries may require different access rights, for example firemen, security companies or police may require access to all facilities, while a mailman only requires access to a mailbox.
International patent application WO 93/14571 discloses a secure entry system utilising a cellular telephone as an electronic key device. In this prior art system a user operates the cellular telephone to transmit RF signals to a lock, allowing a user to operate the buttons on the telephone as he would buttons on a key card to gain access to the secured area. The lock checks whether the user identified by the button operations is on a list of authorised users maintained in the lock memory.
storing a first access code in the first storage means, the first access code being indicative of a predetermined access right to the location;
storing a second access code in a second storage means;
using an electronic key device for requesting access to the location by initiating transmitting the second access code from the second storage means to the lock control unit;
comparing the transmitted second access code with the first access code stored in the first storage means; and